ELTRINGHAM, S K; BOYD, H. Aerial survey of wildfowl in the Highlands of Northern Scotland in the spring of 1959. Wildfowl, [S. l.], v. 11, p. 103–106, 1960. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155700. Acesso em: 4 apr. 2026.